21031003111 has 4 divisors (see below), whose sum is σ = 21031295824. Its totient is φ = 21030710400.

The previous prime is 21031003099. The next prime is 21031003121. The reversal of 21031003111 is 11130013012.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 21031003111 - 2⁵ = 21031003079 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21031003091 and 21031003100.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21031003121) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 43591 + ... + 209671.

It is an arithmetic number, because the mean of its divisors is an integer number (5257823956).

Almost surely, 2^21031003111 is an apocalyptic number.

21031003111 is a deficient number, since it is larger than the sum of its proper divisors (292713).

21031003111 is a wasteful number, since it uses less digits than its factorization.

21031003111 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 292712.

The product of its (nonzero) digits is 18, while the sum is 13.

Adding to 21031003111 its reverse (11130013012), we get a palindrome (32161016123).

Subtracting from 21031003111 its reverse (11130013012), we obtain a palindrome (9900990099).

The spelling of 21031003111 in words is "twenty-one billion, thirty-one million, three thousand, one hundred eleven".